And it is taught in a baraita that Rabbi Eliezer even allows the ritually pure dough placed in the middle to be as large as an egg-bulk, even though dough of that size is susceptible to the halakhot of ritual impurity.

סברוה אידי ואידי בעיסה ראשונה וחולין הטבולין לחלה לא כחלה דמו

The Gemara now explains the reasoning of those who tried to prove from here that Rabbi Eliezer is of the opinion that second-degree ritual impurity cannot impart third-degree ritual impurity upon non-sacred items: They assumed that both this mishna and thisbaraita are referring to cases where the dough is of first-degree impurity. And furthermore, they assumed that all the tanna’im agree that non-sacred food that is untithed with regard to the obligation to separate ḥalla, as its ḥalla has not yet been separated, is not treated like ḥalla as far as its ability to contract third-degree ritual impurity. Rather, it is regarded as generic non-sacred food, which is susceptible only to second-degree impurity.

מאי לאו בהא קמיפלגי דמר סבר אין שני עושה שלישי בחולין

Based on these assumptions the Gemara explains how these authorities understood the tannaitic dispute: What, is it not clear that Rabbi Eliezer and the Rabbis disagree with regard to the following matter: One Sage, Rabbi Eliezer, holds that an item of second-degree impurity cannot impart third-degree impurity to non-sacred items. Therefore, there is no problem placing an egg-bulk of pure dough in the middle, as although it will touch the impure dough and will thereby contract second-degree impurity, nevertheless it is unable to transmit impurity to the pure dough.

ומר סבר שני עושה שלישי בחולין

And one Sage, i.e., the Rabbis, holds that an item of second-degree impurity can impart third-degree ritual impurity to non-sacred items. They therefore prohibit placing an egg-bulk of dough in the middle, as it will assume second-degree impurity status, which, in their opinion, can impart third-degree impurity status upon the pure dough.

Rav Mari, son of Rav Kahana, said that the dispute can be understood differently: Everyone agrees that an item of second-degree ritual impurity cannot impart third-degree ritual impurity to non-sacred items. But here, the dispute concerns another matter, as they disagree with regard to the status of non-sacred food that is untithed vis-à-vis ḥalla, as its ḥalla has not yet been separated. One Sage, i.e., the Rabbis, holds that it is treated like ḥalla with regard to its ability to contract third-degree impurity, and one Sage, Rabbi Eliezer, holds that it is not treated like ḥalla and cannot contract third-degree impurity. Therefore, he permits separating ḥalla in this manner.

And if you wish, say instead that they disagree with regard to a different issue: Everyone agrees that non-sacred food that is untithed with regard to ḥalla is not treated like ḥalla and cannot contract third-degree impurity, and that an item of second-degree ritual impurity cannot impart third-degree ritual impurity to non-sacred items. But here, they disagree with regard to whether or not it is permitted to cause ritual impurity to non-sacred food that is in Eretz Yisrael.

One Sage, Rabbi Eliezer, holds that it is permitted to cause impurity to non-sacred food that is in Eretz Yisrael. Therefore, since the dough placed in the middle cannot impart third-degree ritual impurity status upon the dough designated for ḥalla, there is no reason to prohibit doing so. And one Sage, i.e., the Rabbis, holds that it is prohibited to cause impurity to non-sacred food that is in Eretz Yisrael. Therefore, although the dough of the ritually pure batch will not become impure, nevertheless the Rabbis prohibit separating ḥalla in this manner, as causing the dough in the middle to become impure is prohibited.

בו ביום דרש רבי עקיבא וכו'

§ It is stated in the mishna: On that same day Rabbi Akiva interpreted one of the contradictory verses with regard to the amount of land surrounding the Levite cities as teaching that one may not travel beyond a two-thousand-cubit radius around his city limits on Shabbat. Rabbi Eliezer, son of Rabbi Yosei HaGelili, on the other hand, interprets the contradictory verses as referring to different types of land left for the Levites around their cities.

במאי קא מיפלגי מר סבר תחומין דאורייתא ומר סבר דרבנן

The Gemara asks: With regard to what halakhic matter do they disagree? The Gemara answers: One Sage, Rabbi Akiva, holds that the halakha of Shabbat boundaries is mandated by Torah law, as he bases it on a verse; and one Sage, Rabbi Eliezer, son of Rabbi Yosei HaGelili, holds that the halakha of Shabbat boundaries is mandated by rabbinic law, and he therefore derives other matters from the verse.

§ The Sages taught: On that same day Rabbi Akiva taught that at the time that the Jewish people ascended from the split sea they set their eyes on reciting a song of gratitude to God. And how did they recite the song? In the same manner as an adult man reciting hallel on behalf of a congregation, as his reading enables all who hear to fulfill their obligation, and the congregation listening merely recite after him the chapter headings of hallel. So too, by the sea, Moses said: “I will sing unto the Lord” (Exodus 15:1), and the people said after Moses: “I will sing unto the Lord.” Moses continued and said: “For He is highly exalted” (Exodus 15:1), and they said once again the chapter heading: “I will sing unto the Lord.”

Rabbi Eliezer, son of Rabbi Yosei HaGelili, says: The Jewish people sang just like a minor boy reciting hallel and the congregation who hear him repeat after him all that he says, word for word, as hearing the recital of a minor is insufficient for fulfilling one’s obligation. So too, by the sea, Moses said: “I will sing unto the Lord” (Exodus 15:1), and the people said after Moses: “I will sing to the Lord.” Moses said: “For He is highly exalted,” and they said after him the same words: “For He is highly exalted.”

Rabbi Neḥemya says: They sang the song of the sea like a scribe, a cantor, who recites aloud the introductory prayers and blessings before Shema in the synagogue; as he begins by saying the first words of the blessing, and they repeat after him the initial words and continue reciting the rest of Shema together with him in unison. So too, in the song of the sea, Moses began and then everyone recited the entire song together with him.

במאי קמיפלגי רבי עקיבא סבר לאמר אמילתא קמייתא

The Gemara asks: With regard to what do they disagree? The Gemara answers that they disagree with regard to the interpretation of the verse: “Then Moses and the children of Israel sang this song unto the Lord, and said, saying” (Exodus 15:1). Rabbi Akiva holds that the word “saying,” which indicates that the people sang after Moses, is referring only to the first words of the song, which the people continually repeated: “I will sing unto the Lord” (Exodus 15:1).

And Rabbi Eliezer, son of Rabbi Yosei HaGelili, holds that the word “saying” is referring to every single word, as they would repeat after Moses every word. And Rabbi Neḥemya holds that the phrase “and they said” (Exodus 15:1) indicates that everyone recited the song of the sea together, and the word “saying” means that Moses began singing the song first; and then the rest of the people sang the beginning after him and they all continued in unison.

§ The Sages taught in a baraita that Rabbi Yosei HaGelili taught: At the time that the Jewish people ascended from the sea they resolved to sing a song of gratitude to God. And how did they recite this song? If a baby was lying on his mother’s lap or an infant was nursing from his mother’s breasts, once they saw the Divine Presence, the baby straightened his neck and the infant dropped the breast from his mouth, and they recited: “This is my God and I will glorify Him” (Exodus 15:2). As it is stated: “Out of the mouths of babies and sucklings You have founded strength” (Psalms 8:3).

היה רבי מאיר אומר מנין שאפי' עוברים שבמעי אמן אמרו שירה שנאמר

Rabbi Meir would say: From where is it derived that even fetuses in their mother’s womb recited the song at the sea? As it is stated: